From 2fcdf352df4212ff679d90a1fd63b6469e5f346d Mon Sep 17 00:00:00 2001
From: Richard Hughes <richard@hughsie.com>
Date: Thu, 28 Apr 2022 11:42:08 +0100
Subject: [PATCH] Retry the device ioctl for EAGAIN

---
 libfwupdplugin/fu-udev-device.c | 42 +++++++++++++++++++++++++++++----
 libfwupdplugin/fu-udev-device.h |  9 +++++++
 libfwupdplugin/fwupdplugin.map  |  6 +++++
 3 files changed, 53 insertions(+), 4 deletions(-)

diff --git a/libfwupdplugin/fu-udev-device.c b/libfwupdplugin/fu-udev-device.c
index 5469d66e1..78ad8372a 100644
--- a/libfwupdplugin/fu-udev-device.c
+++ b/libfwupdplugin/fu-udev-device.c
@@ -1375,25 +1375,32 @@ fu_udev_device_close(FuDevice *device, GError **error)
 }
 
 /**
- * fu_udev_device_ioctl:
+ * fu_udev_device_ioctl_full:
  * @self: a #FuUdevDevice
  * @request: request number
  * @buf: a buffer to use, which *must* be large enough for the request
  * @rc: (out) (nullable): the raw return value from the ioctl
+ * @timeout: (nullable): timeout in ms for the retry action, see %FU_UDEV_DEVICE_FLAG_IOCTL_RETRY
  * @error: (nullable): optional return location for an error
  *
  * Control a device using a low-level request.
  *
  * Returns: %TRUE for success
  *
- * Since: 1.3.3
+ * Since: 1.8.1
  **/
 gboolean
-fu_udev_device_ioctl(FuUdevDevice *self, gulong request, guint8 *buf, gint *rc, GError **error)
+fu_udev_device_ioctl_full(FuUdevDevice *self,
+			  gulong request,
+			  guint8 *buf,
+			  gint *rc,
+			  guint timeout,
+			  GError **error)
 {
 #ifdef HAVE_IOCTL_H
 	FuUdevDevicePrivate *priv = GET_PRIVATE(self);
 	gint rc_tmp;
+	g_autoptr(GTimer) timer = g_timer_new();
 
 	g_return_val_if_fail(FU_IS_UDEV_DEVICE(self), FALSE);
 	g_return_val_if_fail(request != 0x0, FALSE);
@@ -1411,7 +1418,14 @@ fu_udev_device_ioctl(FuUdevDevice *self, gulong request, guint8 *buf, gint *rc,
 		return FALSE;
 	}
 
-	rc_tmp = ioctl(priv->fd, request, buf);
+	/* poll if required  up to the timeout */
+	do {
+		rc_tmp = ioctl(priv->fd, request, buf);
+		if (rc_tmp >= 0)
+			break;
+	} while ((priv->flags & FU_UDEV_DEVICE_FLAG_IOCTL_RETRY) &&
+		 (errno == EINTR || errno == EAGAIN) &&
+		 g_timer_elapsed(timer, NULL) < timeout * 1000.f);
 	if (rc != NULL)
 		*rc = rc_tmp;
 	if (rc_tmp < 0) {
@@ -1443,6 +1457,26 @@ fu_udev_device_ioctl(FuUdevDevice *self, gulong request, guint8 *buf, gint *rc,
 #endif
 }
 
+/**
+ * fu_udev_device_ioctl:
+ * @self: a #FuUdevDevice
+ * @request: request number
+ * @buf: a buffer to use, which *must* be large enough for the request
+ * @rc: (out) (nullable): the raw return value from the ioctl
+ * @error: (nullable): optional return location for an error
+ *
+ * Control a device using a low-level request.
+ *
+ * Returns: %TRUE for success
+ *
+ * Since: 1.3.3
+ **/
+gboolean
+fu_udev_device_ioctl(FuUdevDevice *self, gulong request, guint8 *buf, gint *rc, GError **error)
+{
+	return fu_udev_device_ioctl_full(self, request, buf, rc, 0, error);
+}
+
 /**
  * fu_udev_device_pread_full:
  * @self: a #FuUdevDevice
diff --git a/libfwupdplugin/fu-udev-device.h b/libfwupdplugin/fu-udev-device.h
index 38869a94f..6bcb299bf 100644
--- a/libfwupdplugin/fu-udev-device.h
+++ b/libfwupdplugin/fu-udev-device.h
@@ -34,6 +34,7 @@ struct _FuUdevDeviceClass {
  * @FU_UDEV_DEVICE_FLAG_USE_CONFIG:		Read and write from the device config
  * @FU_UDEV_DEVICE_FLAG_OPEN_NONBLOCK:		Open nonblocking, e.g. O_NONBLOCK
  * @FU_UDEV_DEVICE_FLAG_OPEN_SYNC:		Open sync, e.g. O_SYNC
+ * @FU_UDEV_DEVICE_FLAG_IOCTL_RETRY:		Retry the ioctl() call when required
  *
  * Flags used when opening the device using fu_device_open().
  **/
@@ -45,6 +46,7 @@ typedef enum {
 	FU_UDEV_DEVICE_FLAG_USE_CONFIG = 1 << 3,
 	FU_UDEV_DEVICE_FLAG_OPEN_NONBLOCK = 1 << 4,
 	FU_UDEV_DEVICE_FLAG_OPEN_SYNC = 1 << 5,
+	FU_UDEV_DEVICE_FLAG_IOCTL_RETRY = 1 << 6,
 	/*< private >*/
 	FU_UDEV_DEVICE_FLAG_LAST
 } FuUdevDeviceFlags;
@@ -102,6 +104,13 @@ gboolean
 fu_udev_device_ioctl(FuUdevDevice *self, gulong request, guint8 *buf, gint *rc, GError **error)
     G_GNUC_WARN_UNUSED_RESULT;
 gboolean
+fu_udev_device_ioctl_full(FuUdevDevice *self,
+			  gulong request,
+			  guint8 *buf,
+			  gint *rc,
+			  guint timeout,
+			  GError **error) G_GNUC_WARN_UNUSED_RESULT;
+gboolean
 fu_udev_device_pwrite(FuUdevDevice *self, goffset port, guint8 data, GError **error)
     G_GNUC_WARN_UNUSED_RESULT;
 gboolean
diff --git a/libfwupdplugin/fwupdplugin.map b/libfwupdplugin/fwupdplugin.map
index 47250c498..5e425dba1 100644
--- a/libfwupdplugin/fwupdplugin.map
+++ b/libfwupdplugin/fwupdplugin.map
@@ -1034,3 +1034,9 @@ LIBFWUPDPLUGIN_1.8.0 {
     fu_uswid_firmware_new;
   local: *;
 } LIBFWUPDPLUGIN_1.7.7;
+
+LIBFWUPDPLUGIN_1.8.1 {
+  global:
+    fu_udev_device_ioctl_full;
+  local: *;
+} LIBFWUPDPLUGIN_1.8.0;